Modulation of gut microbiota and gut-generated metabolites by bitter melon results in improvement in the metabolic status in high fat diet-induced obese rats

The anti-obesity property of bitter melon powder (BMP) was investigated using a high-fat diet (HFD) obesity model. Obese rats were fed a HFD and treated with BMP for 8 weeks. We observed that BMP could effectively retard the body weight gain and improve the insulin sensitivity compared to the HFD group (p<.05). BMP also showed reduced endotoxin load as lipopolysaccharide-binding protein (LBP) level in the system. 16S rRNA sequencing indicated that BMP dramaticlly increased the relative abundance of Blautia and Allobaculum at the genus level. Metabolomic data revealed that dietary BMP changed metabolic profiles, including the metabolism of organic acids, amino acids and sugars. Additionally, some significant correlations was observed between specific gut microbiota at the genus level and effective biomarkers. These results reveal that the inhibition of insulin resistance and anti-inflammatory effect of BMP in obesity are illustrated with the restoration of gut microbiota and gut-generated metabolites.